1. Field of Invention
The present invention relates to a method for separating luminance and chrominance. More particularly, the present invention relates to a method for separating a luminance signal and a chrominance signal of a composite TV analog signal.
2. Description of Related Art
In a conventional color TV, the analog TV signal is generally transmitted in the form of a composite signal including luminance (Y) plus chrominance (C). Thus, the process of separating the composite signal into the luminance signal and the chrominance signal is essential, and this process is often carried out by a comb filter. In order to obtain a better filtering result, still image signals are always filtered by a three-dimensional (3D) comb filter, and image signals in which motions exist are always filtered by a two-dimensional (2D) comb filter. However, the composite signal usually includes concurrently the still image signal and the image signal in which the motions exist. Consequently, if the composite signal is filtered only by the 3D comb filter or only by the 2D comb filter, the composite signal cannot be separated or filtered very well.